N electric fuses



v L. KALMBACI'L Electric-Fuses.

.Patented lun6.29, l875,

eHaRLnsL. KALMBACH', or nieuiroxn, VIRGINIA..

IMPRVEMENT IN ELECTRlC FUSES.

Specification forming part of Letters Patent No. /LQQE, dated June 29, 1575; application filed June 24,1874.

To alt w/Lom liv may concern-.-

Be it known that 1', GHARLEs L. KALMBACH', M. E., of Richmond, in the county ot' Henrico and State ot Virginia, haveinvented a new and useful Improvement in Primers for Exploding Mines j and I do hereby declare that the following is a full, clear, and exact description ot' the same, reference being had to the annexed drawine.

The object ot' my invention is to make a f'ulminate-primer which may be safely handled and usedwith absolute certainty and etiect. "io' this end l take a wooden cylindrical plug, A, made conical at the end intended to rest on the charge, shaped substantially' as shown, the diameter ot' which is suiiicient to allow it to be introduced -into the hole `0r cartridge containing` the charge. For fastening,` a cartridge conveniently to this wooden case, I out a groove around the ease above the conical part, as shown, into which groove the upper edge of the cartridge may be bent or tied. I then take the wires or fuse and pass through the small hole in the axis et' the case. lt wires are used, the lower end is held over a lamp-chimney until lthe gutta-pereha becomes plastic, when itis shoved back with moistened iiugers until a lump is formed large enough to close one endet' a pieceotl quill about au inch in length. '.lhe naked wires are cut ott' close to this lump, and it, with the ends otl wire just protruding, is forced into the quill. wire ends, being' visible through the sides ot' the quill, may bf adjusted so as to form proper terminal poles. \\'hen the guttapercha has cooled enough to become hard, it will be iirmlyI united with the quill, and the latter may he loaded with pure t'uhuiua-te and closed with a small wad ot' raw cotton. Then the quill and wires are inserted in ai glass vial ot' suitable size, and more or less t'ulminate, as may he desired, is poured into the vial, stoppt-red with more raw cotton, and covered with sott pitch, through which asmall cork is l'orced, when morel pitch is put over the cork. lhe rial is then diuwn bark into a recess i'ornred in the rohe, care being laken to put pitch enough in the roi-ess to entirely surround the vial.

When fuse is to be used it is of course not necessary to use the quill, and the vial being,l loaded, the end ot' the fuse is simply introduced and sealed, when thewial and fuse are carefully forced back into the pitch-lined recess ot' the cone, and the primer is ready. For light charges, fired by the spark, the Vial may be dispensed with, and the quill alone, sealed in a similar manner, used. By this means I make a fulminate primer which may, with safety, be carelessly handled, and which may 'ee kept indelinitely without being` injuriously attected.

I am aware that copper capsules have been employed for such primers, land I do not there,- i'ore claim in this connection any impervious capsule. My claim is limited to the use oi' glass capsules, as I have t'ound that it is sat'er to use them than metallic ones, as in case ot' premature explosion ot' the capsule the nitroglyccrine is liable to be exploded by the tric` tion ot' the flying` particles ol' metal, while a glass capsule will be, by the explosion ot'- the i'ulminate, broken into a. tine dust, which will not explode nitro-glyceriue except by the sudden pressure exerted by the fulminatewhcn the primer is iirnily held in contact with the churgi.

lVhat l claim as my invention, and desire to secure by Letters Patent, isy l. A t'ulminate primer constructed by sealing a ,glass vial containing the fuhniuate ot' mercury hermetic-ally in a chambcred wooden block, substantially as set forth.

L. ln combination with the liringiwircs, a quill within which the ends oi' the wires'a-re adjusted in proper relation to one another, substantially as set forth.

In testimony whe-reet' I hare signed my name to this` specification in the presence oll two subscribing' witnesses.

ll'itnesses:

Asa ltocnus, J. ll. Hanni'. 

